Method and apparatus utilizing ionizing and microwave radiation for saturation determination of water, oil and a gas in a core sample

Abstract

A system for determining the relative permeabilities of gas, water and oil in a core sample has a microwave emitter/detector subsystem and an X-ray emitter/detector subsystem. A core holder positions the core sample between microwave absorbers which prevent diffracted microwaves from reaching a microwave detector where they would reduce the signal-to-noise ratio of the microwave measurements. The microwave emitter/detector subsystem and the X-ray emitter/detector subsystem each have linear calibration characteristics, allowing one subsystem to be calibrated with respect to the other subsystem. The dynamic range of microwave measurements is extended through the use of adjustable attenuators. This also facilitates the use of core samples with wide diameters. The stratification characteristics of the fluids may be observed with a windowed cell separator at the outlet of the core sample. The condensation of heavy hydrocarbon gas and the dynamic characteristics of the fluids are observed with a sight glass at the outlet of the core sample.

What is claimed is: 
     
       1. An apparatus for determining the amounts of water, oil and gas in a core sample, the core sample having a matrix defining an open space occupied by water, oil and gas including heavy hydrocarbon gas flowing therein, the apparatus comprising: a core holder having an inlet, an outlet, and a core sleeve for holding said core sample, the core sleeve being surrounded at least partially by microwave absorptive material for absorbing microwave radiation diffracted around said sleeve thus preventing the diffracted radiation from emerging from the core holder;   means for illuminating an area of said core sample within the core holder with focused microwave radiation of a known intensity;   means for adjustably attenuating the microwave radiation to ensure that the power level of the microwave radiation emerging from said core sample is within a measurable range;   means for measuring the microwave radiation emerging from said core sample to determine the amount of water in said open space of said core sample;   means for illuminating an area of said core sample within the core holder with ionizing electromagnetic radiation of a known intensity simultaneously with said microwave radiation;   means for measuring the ionizing electromagnetic radiation transmitted through said core sample to determine the amount of oil in said open space of said core sample;   information analyzing means, interfaced with said means for measuring microwave radiation and said means for measuring ionizing radiation, for comparing a weight of said core sample without any water or oil therein to said amount of said oil and of said water to determine said amount of gas occupying portions of said open space not occupied by said water and said oil;   means attached at the outlet of said core holder for optically examining the condensation of heavy hydrocarbon gas and the oil and water flowing from the core sample representative of said gas and the oil and water inside said core sample; and   means attached at the outlet of said core holder for optically examining the stratification of the water and oil flowing from the core sample representative of said water and oil inside said core sample.   
     
     
       2. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, wherein said means for optically examining the condensation and the oil and water comprises a sight glass cell for measuring the condensation of heavy hydrocarbon gas and the oil and water at the outlet of said core sample facilitating a determination of the activity inside said core sample. 
     
     
       3. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, wherein said means for optically examining the stratification comprises a windowed cell separator for separating, by density, the oil and water at the outlet of said core sample facilitating the measurement of oil and water levels inside said core sample. 
     
     
       4. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, further comprising means for flowing a quantity of said oil through said core sample. 
     
     
       5. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, further comprising means for flowing a quantity of said water through said core sample. 
     
     
       6. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, further comprising means for flowing a quantity of said gas through said core sample. 
     
     
       7. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, further comprising means for flowing a quantity of said gas and a quantity of said oil through said core sample. 
     
     
       8. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, further comprising means for flowing a quantity of said water and a quantity of said oil through said core sample. 
     
     
       9. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claim 1, further comprising means for flowing a quantity of said gas, a quantity of said water and a quantity of said oil through said core sample. 
     
     
       10. An apparatus for determining the amounts of an open space in a core sample occupied by water, oil and gas as defined in claims 1, 2, 3, 4, 5, 6, 7, 8 or 9, further comprising means for moving each said means for illuminating and measuring with respect to said core sample to make a plurality of saturation measurements in a short time. 
     
     
       11. A method of determining the amounts of water, oil and gas in a core sample, the core sample having a matrix defining an open space occupied by water, oil and gas including heavy hydrocarbon gas flowing therein, the method comprising steps of: illuminating an area of said core sample with focused microwave radiation of a known intensity;   attenuating the microwave radiation to ensure that the power level of the microwave radiation emerging from said core sample is within a range capable of being measured;   shielding regions outside the core sample from said microwave radiation to prevent microwave radiation which has not passed through the core sample from being measured;   measuring microwave radiation emerging from said core sample to determine an amount of water in open space of said core sample;   illuminating X-rays on said core sample simultaneously with said microwave radiation;   measuring X-rays emerging from said core sample to determine an amount of oil in said open space of said core sample;   comparing the void volume of said core sample without any water or oil therein to the volume of said amount of oil and the volume of said amount of water to determine the volume of gas occupying portions of said open space not occupied by said water and said oil; and   viewing the condensation of heavy hydrocarbon gas and the oil and water flowing from the core sample representative of said gas and the oil and water facilitating a determination of activity inside said core sample.